It used to be that if you hide the Norton Toolbar and landed on a website rated Caution, you would see a popup (not sure what to call it) from the Toolbar. It went away when clicking on something else, though, so you could miss it. Last time I checked the behaviour (more than a year ago), you would be on a website rated Caution and Norton would not let you know, if the toolbar was hidden. Last time I checked, a "full page block" of a website rated Warning by the Norton Toolbar, was not actaully blocking the website. You needed Norton DNS configured for the website to actually be blocked.